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PERFORMANCE EVALUATION OF SEVERAL FUSION APPROACHES FOR CCD/SAR IMAGES

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Chinese Geographical Science 2003年第1期13卷 91-96页

作者： WANG Yan-li, CHEN Zhe(school of Automation Science and Electrical engineering,{2., {3. 100083. P. R. china) school of Automation Science and Electrical engineering，{2.， {3. 100083. P. R. china

Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.

关键词： image fusion performance evaluation CCD image SAR image

Electrochemical Studies of Lithium Intercalation into Graphite Film Electrode for Li^+-ion Batteries

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International Journal of Minerals,Metallurgy and materials 2000年第1期14卷 48-50页

作者： Chuangang Lin Weihua Qiu Qingguo Liu material Science and engineering {2., {3. of Science and Technology beijing, beijing 100083. china material Science and engineering {2. University of Science and Technology Beijing Beijing 100083 China

To study the electrochemical kinetic properties of the Li/Graphite system, cycle voltammerty (CV), ac-impedance and chro- noamperometry (CA) techniques have been used. The results showed that the diffusion of lithium ions in Li_xC_6 is the rate-determining step. The chemical diffusion coefficients of lithium (D_Li) have been estimated for different x values. As for the same material, the value of D_Li was calculated in order to compare the differences among the three techniques.

关键词： electrochemical studies graphite Li^+-ion batteries

Prediction and Control of both Wrinkle Limit and Fracture Limiton Cylindrical Cup Deep-drawing(Ⅱ)

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International Journal of Minerals,Metallurgy and materials 1999年第3期13卷 201-204页

作者： Junxiang Lei Yonglin Kang(Department of Mechanical engineering, Yantai university, Yantai 2.4005, {2.)({3. Science and engineering school, university of Science and Technology beijing, beijing 100083. china) Department of Mechanical engineering Yantai University Yantai 264005 China material Science and engineering {2. University of Science and Technology Beijing Beijing 100083 China

The prediction and control criterion of both the wrinkle limit and fracture limit on the cylindrical cup deep-drawing are given, and the prediction and control diagram of both the wrinkle limit and fracture limit are also given. The results show that it is suitable for no-flange cylindrical cup deep-drawing, narrow-flange cylindrical cup deep-drawing, wide-flange cylindrical cup deep-drawing/expanding compound forming and rigid punch expanding forming.

关键词： cylindrical cup wrinkle limit fracture limit deep-drawing expanding forming compound forming

A New Scheme and Microstructural Model for 3. Full 5-directional Braided Composites

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Chinese Journal of aeronautics 2010年第1期23卷 61-67页

作者： Zhang Fan,Liu Zhenguo,Wu Zhe,Tao Guoquan school of Aeronautic Science and engineering,{2. {3. of aeronautics and astronautics,{2. 100191,china [a] school of Aeronautic Science engineering Beijing University of Aeronautics astronautics Beijing 100191 China

Three-dimensional（3.D）braided composites are a kind of advanced ones and are used in the aeronautical and astronautical fields more widely. The advantages, usages, shortages and disadvantages of 3. braided composites are analyzed, and the possible approach of improving the properties of the {2.s is presented, that is, a new type of 3. full 5-directional braided composites is developed. The methods of making this type of preform are proposed. It is pointed out that the four-step braiding which is the most possible to realize industrialized production almost has no effect on the composites＇ properties. By analyzing the simulation model,the advantages of the {2. compared with the 3. 4-directional and 5-directional {2.s are presented. Finally, a microstructural model is analyzed to lay the foundation for the future theoretical analysis of these composites.

关键词： 3. braided fabrics four-step braiding 3. full 5-directional braided composites preform microstructure

Laser Shock Processing of an Austenitic Stainless Steel and a Nickel-base Superalloy

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Journal of materials Science & Technology 2003年第5期19卷 402-404页

作者： Huaming WANG, Xijun SUN and Xiaoxuan LILaboratory of Laser materials Processing and Surface engineering, {2. of materials Science and engineering, Beihang university (formerly beijing university of aeronautics and astronautics), beijing 100083. china Lab. of Laser Mat. Proc. Sch. of Mat. Sci. and Eng. Beijing Univ. of Aero. and Astron. Beijing 100083 China

An austenitic stainless steel 1Cr18Ni9Ti and a solid solution-strengthened Ni-base superalloy GH3. were shock processed using a Q-switched pulsed Nd-glass laser. Microstructure, hardness and residual stress of the laser shock processed surface were investigated as functions of laser processing parameters. Results show that high density of dislocations and fine deformation twins are produced in the laser shock processed surface layers in both the austenitic stainless steel and the nickel-base superalloy. Extensive strain-induced martensite was also observed in the laser shock processed zone of the austenitic steel. The hardness of the laser shock processed surface was significantly enhanced and compressive stress as high as 400 MPa was produced in the laser shock processed surface.

关键词： Laser shock processing Austenitic stainless steel Nickel-base superalloy Surface mechanical properties Residual stress

Some Properties of The Solutions of Higher Analogue of The Painlevé Equation

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Acta Mathematicae Applicatae Sinica 2006年第1期22卷 59-64页

作者： Ye-zhou Li school of Science,beijing {2. of Posts and Elecommunications,beijing 100876,china school of Aeronautical Sciences and engineering,beijing {2. of aeronautics and astronautics,beijing {12. school of Science Beijing University of Posts Elecommunications Beijing 100876 China school of Aeronautical Sciences engineering Beijing University of Aeronautics astronautics Beijing 100083

In this paper, we investigate the value distribution properties for the solution w（z） of higher-order Painlevé equations. We prove that the Nevanlinna＇s second main inequality for w（z） is reduced to an asymptoti... 详细信息

关键词： Painlevé equation the second main inequality value distribution

Sticking-up Behaviors and Surface Friction of IF Electrogalvanized Sheet Steel in Forming

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International Journal of Minerals,Metallurgy and materials 1999年第1期13卷 61-63,68页

作者： Jiming Hu Jixun Wu Yanping Lu Yanrong Zhu (material Science and engineering {2., {3. of Science and Technology beijing, beijing 100083. china) Univ of Science and Technology Beijing Beijing China

X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solution system. It was shown that the picking-up of the zinc coating on die strengthened with the increasing of friction factor which was originally affected by the coating's structure. Duing forming, (00X) planes (X= 2. 4) preferential orientation of zinc deposits increased, which resulted in enhanc ing the coating's friction behaviors. Therefore, the forming mechanism of electrogalvedzed deposit was demonstrated that both friction and the stricking -up behaviors of the coating are intensified simultaneously and affect each other.

关键词： electrogalvanized deposit forming friction factor

Comparison of Ferrite Refinement Mechanisms by Different Processing Schedules in 08 and 2.Mn Steels

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Journal of university of Science and Technology beijing 2001年第3期8卷 218-223页

作者： Ping Yang Feng’e Gui, Shicai Ma material Science and engineering {2., {3. of Science and Technology beijing, beijing 100083. china Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

The influence of deforming temperature on ferrite refinement was analyzed by comparing the microstructures obtained by deformation at above A(r3., in two-phase region of (alpha + gamma) and at below A(t) in clean 08 and 2.Mn steels. The results indicate that ferrite refinement through strain induced transformation by deformation at above A(r3. is more effective than that by deformation simply through ferrite dynamic recrystallization. The main problem of ferrite refinement by deformation at below A(r3. is the inhomogeneity of microstructure which is controlled by the orientations and sizes of ferrite grains and the distribution of second phases. Ferrite dynamic recrystallization after strain induced transformation can further effectively refine ferrite.

关键词： clean carbon steel strain induced transformation grain refinement ferrite dynamic recrystallization

Application of Tandem Cascade to Design of Fan Stator with Supersonic Inflow

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Chinese Journal of aeronautics 2010年第1期23卷 9-14页

作者： Li Qiushi,Wu Hong,Zhou Sheng school of Jet Propulsion,beijing {2. of {3. and astronautics,beijing 100191,china [a] school of Jet Propulsion Beijing University of Aeronautics astronautics Beijing 100191 China

This article proposes a tandem cascade constructed to tackle the thorny problem of designing the high-loaded stator with a supersonic inflow and a large turning angle. The front cascade adopts a supersonic profile to reduce the shock wave intensity turning the flow into subsonic,while the rear cascade adopts a subsonic profile with a large camber offering the flow a large turning angle. It is disclosed that the losses would be minimized if the leading edge of the rear cas- cade lies close to the pressure side of the front cascade at a distance of 2.% pitch in pitch-wise direction without either axial spacing or overlapping in axial direction. The 2. numerical test results show that,with the inflow Mach number of 1.2. and the turning angle of 52. ,the total pressure loss coefficient of the tandem cascade reaches 0. 106 ,and the diffusion factor 0. 745. Finally,this article has designed and simulated a high-loaded fan stage with the proposed tandem stator,which has the pressure ratio of 3.15 and the efficiency of 86.3.% at the rotor tip speed of 495.3. m/s.

关键词： fan/compressor tandem cascade stator supersonic inflow